在Java中如何使用构造器链实现对象初始化_OOP构造器链方法分享

public class Student {
    private String name;
    private int age;
    private String grade;

    // 主构造器：包含所有参数
    public Student(String name, int age, String grade) {
        this.name = name;
        this.age = age;
        this.grade = grade;
    }

    // 构造器2：只提供姓名和年龄，默认班级为 "未分配"
    public Student(String name, int age) {
        this(name, age, "未分配"); // 调用主构造器
    }

    // 构造器3：只提供姓名，默认年龄18，班级未分配
    public Student(String name) {
        this(name, 18, "未分配"); // 仍调用主构造器
    }

    // getter 方法（便于测试）
    public String getInfo() {
        return "姓名：" + name + "，年龄：" + age + "，班级：" + grade;
    }
}

public class Person {
    protected String name;

    public Person(String name) {
        this.name = name;
    }
}

public class Student extends Person {
    private String major;

    public Student(String name, String major) {
        super(name);              // 先调用父类构造器
        this.major = major;       // 再初始化子类字段
    }
}